Buggy code:
public class NEIServerConfig { private static MinecraftServer server ; public static Logger logger = LogManager . getLogger ( "NotEnoughItems" ) ; public static File saveDir ; public static ConfigFile serverConfig ; public static Map < Integer , NBTTagCompound > dimTags = new HashMap < Integer , NBTTagCompound > ( ) ; public static HashMap < String , PlayerSave > playerSaves = new HashMap < String , PlayerSave > ( ) ; public static ItemStackMap < Set < String > > bannedItems = new ItemStackMap < Set < String > > ( ) ; public static void load ( World world ) { } public static File getSaveDir ( World world ) { } private static void loadWorld ( World world ) { } private static void loadConfig ( ) { } private static void setDefaultFeature ( String featurename , String ... names ) { } private static void saveWorld ( int dim ) { } public static boolean canPlayerPerformAction ( String playername , String name ) { } public static boolean isPlayerInList ( String playername , Set < String > list , boolean allowCards ) { } public static boolean isActionDisabled ( int dim , String name ) { } public static void disableAction ( int dim , String name , boolean disable ) { } public static HashSet < String > getPlayerList ( String tag ) { } public static void addPlayerToList ( String playername , String tag ) { } public static void remPlayerFromList ( String playername , String tag ) { } private static void savePlayerList ( String tag , Collection < String > list ) { } private static void loadBannedItems ( ) { NEIServerConfig . bannedItems . clear ( ) ; File file = new File ( NEIServerConfig . saveDir , "banneditems.cfg" ) ; if ( ! ( file . exists ( ) ) ) { NEIServerConfig . bannedItems . put ( new net . minecraft . item . ItemStack ( Blocks . command_block ) , new HashSet < String > ( Arrays . asList ( "NONE" ) ) ) ; NEIServerConfig . saveBannedItems ( ) ; return ; } try { FileReader r = new FileReader ( file ) ; int line = 0 ; for ( String s : IOUtils . readLines ( r ) ) { if ( ( ( s . charAt ( 0 ) ) == '#' ) || ( ( s . trim ( ) . length ( ) ) == 0 ) ) continue ; int delim = s . lastIndexOf ( '=' ) ; if ( delim < 0 ) { NEIServerConfig . logger . error ( ( ( "line<seq2seq4repair_space>" + line ) + ":<seq2seq4repair_space>Missing<seq2seq4repair_space>=" ) ) ; continue ; } try { <START_BUG> NBTTagCompound key = JsonToNBT . func_180713_a ( s . substring ( 0 , delim ) ) ; <END_BUG> Set < String > values = new HashSet < String > ( ) ; for ( String s2 : s . substring ( ( delim + 1 ) ) . split ( "," ) ) values . add ( s2 . trim ( ) ) ; NEIServerConfig . bannedItems . put ( InventoryUtils . loadPersistant ( key ) , values ) ; } catch ( Exception e ) { NEIServerConfig . logger . error ( ( ( ( "line<seq2seq4repair_space>" + line ) + ":<seq2seq4repair_space>" ) + ( e . getMessage ( ) ) ) ) ; } } r . close ( ) ; } catch ( Exception e ) { throw new RuntimeException ( e ) ; } } public static void saveBannedItems ( ) { } public static PlayerSave forPlayer ( String username ) { } public static void loadPlayer ( EntityPlayer player ) { } public static void unloadPlayer ( EntityPlayer player ) { } public static boolean authenticatePacket ( EntityPlayerMP sender , PacketCustom packet ) { } }

Fix:
NBTTagCompound key = JsonToNBT . getTagFromJson ( s . substring ( 0 , delim ) ) ;